Power supply fault

[drogheda1]

HI, I HAVE A TAGAN TG800-U25 AND ITS NOT COMING ON. THE CAPACITORS LOOK GOOD AND THE FUSE LOOKS OK. IVE TRIED IT IN MY PSU TESTER, NO JOY. ANY MORE IDEAS?

 

[socialfox]

Not to be rude or anything but the problem is with the power supply brand, TAGAN is not a famous power supply brand it probably uses low quality parts and for such reasons fails a lot just like all those other low quality power supplies. Here is a newegg review for your power supply:

http://www.newegg.com/Product/Product.aspx?Item=N82E16817811004&name=Power-Supplies

My advice is to stick to good brand power suppy brands like Antec, XFX, Seasonic, PC power and Cooling, Corsair etc.

 

[InvalidError]

If the PSU won't turn on with the paper-clip "test" or a PSU tester and the fuse is OK then there isn't much that can be done about it unless you have access to a reasonably well equipped electronics lab that can enable you to trace the problem's source.

Poking around live circuitry operating at 200-400V with pointy probes is not for everybody. The prerequisite reverse-engineering to determine what needs probing can be exhausting as well.

 

[socialfox]

To anyone reading this thread, don't click on the link, its probably spam.

 

[bigcyco1]

To anyone reading this thread, don't click on the link, its probably spam.

Thanks i won't click on it

 

[jemm]

I assume it is a spare PSU since you´ve listed a Corsair AX850 on your signature.

Be careful tough if you are dealing with capacitors on old PSUs -- Teen electrocuted while working on unplugged computer http://www.tomshardware.com/forum/1733-65-teen-electrocuted-working-unplugged-computer

 

[drogheda1]

holy *** man

 

[socialfox]

Hahah, I can just imagine the face your making knowing you risked your life right now. I generally open my power supplies after a few days of disconnecting them from the computer and just leaving it out. Though reading that made me feel uneasy knowing there is still a charge

 

[InvalidError]

I generally open my power supplies after a few days of disconnecting them from the computer and just leaving it out.

The 5VSB converter in ATX PSUs will bleed the main caps within 30 seconds from unplugging. A simple way to know if it is safe to pull a PSU out is to leave it connected to the motherboard until the 5VSB LED goes out, which indicates that primary caps have discharged below the point where the 5VSB supply can operate. This takes 10-30 seconds depending on load on 5VSB and the size of primary caps.

No need to wait for days.

 

[socialfox]

The 5VSB converter in ATX PSUs will bleed the main caps within 30 seconds from unplugging. A simple way to know if it is safe to pull a PSU out is to leave it connected to the motherboard until the 5VSB LED goes out, which indicates that primary caps have discharged below the point where the 5VSB supply can operate. This takes 10-30 seconds depending on load on 5VSB and the size of primary caps.

No need to wait for days.

Appreciate the advice, will keep it in mind from now on instead of wasting days to open a power supply !

Thanks,

Socialfox

 

[drogheda1]

yea thanks. this power supply wasn't in the pc being used, its been in the garage for quite sometime so plenty of time to discharge. still, glad i heard of that story!

 

[jemm]

How a capacitor is charged and discharged in a circuit depend upon capacitance and voltage. Perhaps you have to calculate it using some equations to make sure how long it takes to discharged.

You can use this Capacitor Discharge Calculation for your convenience http://hyperphysics.phy-astr.gsu.edu/hbase/electric/capdis.html

 

[InvalidError]

How a capacitor is charged and discharged in a circuit depend upon capacitance and voltage.

That only tells you how much energy is stored in it. Without a load attached, capacitors can maintain a charge for a potentially very long time if they have very low internal current leakage.

In ATX PSUs, the 5VSB supply will drain capacitors to relatively safe but still potentially unpleasant voltages within 30 seconds.